Department of Nuclear Medicine, The Third Affiliated Hospital of Soochow University, No. 185, Juqian Street, Changzhou, 213003, Jiangsu Province, China.
Changzhou Key Laboratory of Molecular Imaging, Changzhou, Jiangsu Province, China.
J Nucl Cardiol. 2022 Aug;29(4):1520-1533. doi: 10.1007/s12350-020-02483-9. Epub 2021 Jan 27.
Left ventricular diastolic dyssynchrony (LVDD), a dyssynchronous relaxation pattern, has been known to develop after myocardial damage. We aimed to evaluate the dynamic changes in LVDD in the early stage of acute myocardial infarction (AMI) by phase analysis of technetium methoxyisobutylisonitrile (Tc-MIBI) single-photon emission computed tomography (SPECT) gated myocardial perfusion imaging (GMPI) and explore its relationship with the progression of left ventricular remodeling (LVR).
The left anterior descending coronary arteries of 16 Bama miniature swine were occluded with a balloon to build AMI models. Animals were imaged by SPECT GMPI before AMI and at 1 day, 1 week and 4 weeks after AMI, and quantitative analysis was performed to determine the extent of left ventricle (LV) perfusion defects, left ventricular systolic dyssynchrony (LVSD) and the LVDD parameters: phase histogram bandwidth (PBW) and phase standard deviation (PSD). Echocardiography was simultaneously applied to evaluate left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and the LVDD parameters: Te-12-diff and Te-12-SD. Myocardial injury markers were measured, and 12-lead ECGs were performed. The degree of LVR progression was defined as ΔLVESV (%) = (LVESV - LVESV)/LVESV.
Thirteen swine completed the study. LVDD parameters changed dynamically at different time points after AMI. LVDD occurred as early as 1 day after AMI, peaked at 1 week, and trended toward a partial recovery at 4 weeks. Phase analysis on SPECT GMPI showed a significant correlation with tissue Doppler imaging for the assessment of LVDD during the longitudinal evaluation (r = 0.569 to 0.787, both P <0.05). During the univariate and multivariate regression analyses, the LVDD parameters PBW and PSD as of 1 day after AMI were significantly associated with the progression of LVR, respectively (PBW, β = 0.004, 95% CI 0.001 to 0.007, P = 0.024; PSD, β = 0.008, 95% CI 0.000 to 0.017, P = 0.049). Adjusted smooth curve fitting and threshold effect analysis indicated PBW and PSD break-point values of 142° and 60.4°, respectively, to predict the progression of LVR after AMI.
Phase analysis of SPECT GMPI can accurately and reliably characterize LVDD. LVDD occurred on the first day after AMI, reached its peak at 1 week, and partially recovered at 4 weeks after AMI. LVDD as evaluated by phase analysis of SPECT GMPI early after AMI was significantly associated with the progression of LVR. The early assessment of LVDD after AMI may provide helpful information for predicting the progression of LVR in the future.
左心室舒张不同步（LVDD）是一种不同步弛豫的模式，已知其在心肌损伤后发展。我们旨在通过锝-99m 甲氧基异丁基异腈（Tc-MIBI）单光子发射计算机断层扫描（SPECT）门控心肌灌注成像（GMPI）相位分析评估急性心肌梗死（AMI）早期的 LVDD 动态变化，并探讨其与左心室重构（LVR）进展的关系。
用球囊阻塞 16 头巴马小型猪的左前降支冠状动脉，建立 AMI 模型。动物在 AMI 前和 AMI 后 1 天、1 周和 4 周进行 SPECT GMPI 成像，并进行定量分析，以确定左心室（LV）灌注缺损、左心室收缩不同步（LVSD）和 LVDD 参数：相位直方图带宽（PBW）和相位标准差（PSD）的程度。同时应用超声心动图评估左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室射血分数（LVEF）和 LVDD 参数：Te-12-diff 和 Te-12-SD。测量心肌损伤标志物，并进行 12 导联心电图检查。LVVR 进展的程度定义为ΔLVESV（%）=（LVESV-LVESV）/LVESV。
13 头猪完成了研究。AMI 后不同时间点 LVDD 参数发生动态变化。LVDD 早在 AMI 后 1 天就出现，在 1 周时达到高峰，并在 4 周时呈部分恢复趋势。SPECT GMPI 的相位分析与组织多普勒成像在纵向评估中对 LVDD 的评估具有显著相关性（r=0.569 至 0.787，均 P<0.05）。在单变量和多变量回归分析中，AMI 后 1 天的 LVDD 参数 PBW 和 PSD 与 LVR 的进展显著相关（PBW，β=0.004，95%CI 0.001 至 0.007，P=0.024；PSD，β=0.008，95%CI 0.000 至 0.017，P=0.049）。调整后的平滑曲线拟合和阈值效应分析表明，142°和 60.4°分别为 PBW 和 PSD 的截断值，可预测 AMI 后 LVR 的进展。
SPECT GMPI 的相位分析可准确可靠地描述 LVDD。AMI 后第 1 天出现 LVDD，第 1 周达到高峰，第 4 周部分恢复。AMI 后早期 SPECT GMPI 相位分析评估的 LVDD 与 LVR 的进展显著相关。AMI 后早期评估 LVDD 可能为预测未来 LVR 的进展提供有价值的信息。
